Hydrochloric Acid → 2-[(2S)-2-Methyl-1-piperazinyl]oxazolo[5,4-b]pyridine

HRID 394509Notes

Reaction equation

HRID 394509 reaction equation
C([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[O:15][C:16]3[C:21]([N:22]=2)=[CH:20][CH:19]=[CH:18][N:17]=3)[C@@H:10]([CH3:23])[CH2:9]1)C1C=CC=CC=1.Cl.C([O-])=O.[NH4+]>CO.[Pd]>[CH3:23][C@H:10]1[CH2:9][NH:8][CH2:13][CH2:12][N:11]1[C:14]1[O:15][C:16]2[C:21]([N:22]=1)=[CH:20][CH:19]=[CH:18][N:17]=2

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 2723923Ammonium formateHCID 54299137HCID 54299137, compound

Product 1

HCID 539594392-[(2S)-2-Methyl-1-piperazinyl]oxazolo[5,4-b]pyridineYield 76%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Procedure

To a solution of (S)-2-(4-benzyl-2-methyl-piperazin-1-yl)-oxazolo[5,4-b]pyridine (prepared according to the method of Example 16, Step A, 30 g, 97 mmol) in methanol (970 mL) was added hydrogen chloride (5.85 M in methanol, 20 mL, 116 mmol), ammonium formate (122 g, 1.95 mol), and 10% palladium on carbon (60 g, 200 wt %). This mixture was stirred at reflux for 50 min, cooled, and filtered through Celite. The filtrate was concentrated, diluted with saturated aqueous sodium bicarbonate, and extracted with chloroform (1×) followed by 10% isopropanol/chloroform (4×). The combined organic extracts were dried over sodium sulfate, filtered, and evaporated to give 16 g (76%) of the title compound of Example 16, Step B as a green oil. 1H NMR (CDCl3, 400 MHz) δ 7.89 (m, 1H), 7.53 (m, 1H), 7.09 (m, 1H), 4.42 (m, 1H), 4.11 (d, 1H), 3.35 (td, 1H), 3.09-3.03 (c, 2H), 2.85 (d, 1H), 2.82 (td, 1H), 1.38 (d, 3H); MS (APCI) 219 (MH+).

Workup

  1. temperatureat reflux for 50 min
  2. temperaturecooled
  3. filtrationfiltered through Celite
  4. concentrationThe filtrate was concentrated
  5. additiondiluted with saturated aqueous sodium bicarbonate
  6. extractionextracted with chloroform (1×)
  7. dry with materialThe combined organic extracts were dried over sodium sulfate
  8. filtrationfiltered
  9. customevaporated

Sources & evidence

ORD record
ord-27c94aa00ad544d89a40a8f1c96e01df
Source dataset
uspto-grants-2003_08
Patent number
US06602875B2

Reaction notes

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